RICHMOND, June 28 -- The chairman of the Virginia Republican Party alleged Monday that efforts to register new voters have resulted in a "coordinated and widespread effort to commit voter fraud," and Democrats responded by accusing the GOP of trying to suppress minority voting.

In a conference call with reporters, Del. Jeffrey M. Frederick (R-Prince William), the chairman of the state party, seized on the arrests last week of three paid canvassers charged with submitting false names on voter registration forms in Hampton.

The controversy comes during one of the most aggressive efforts in a generation to register new voters, especially African Americans, in Virginia.

Convinced that there are tens of thousands of unregistered African Americans and otherwise Democratic-leaning Virginia residents, the Democrats are trying to register 151,000 new voters before the Oct. 6 deadline. A dozen other private organizations have sent canvassers into the streets to register voters. Democrats think this is their best chance of carrying the state in a presidential election since 1964.

Frederick said the criminal charges in Hampton prove that some groups are trying to register voters through fraudulent means. "Unfortunately, there appears to be a coordinated and widespread effort in Virginia to commit voter fraud," he said.

Frederick said the state Republican Party has obtained an affidavit from a Richmond woman who contends that her Social Security number was used by someone who was trying to register to vote.

Frederick made a public plea for people not to register when approached by a canvasser because of the risk of falling victim to identity theft. "Identify theft is a serious problem. . . . Virginians should exercise caution when approached by a stranger who asks for their information" to register to vote.

Local election officials and police were surprised by Frederick's comments. They said they have found no evidence of fraud or attempts to steal personal information by the presidential campaign of Sen. Barack Obama (D-Ill.) or other organizations trying to register voters.

Virginia Democrats said Frederick and the GOP are trying to suppress efforts to register voters because they are afraid the new voters could tip Virginia into the Democratic column on Election Day.

"Clearly this is a local problem that Jeff Frederick is trying to blow up into a statewide issue," said Jared Leopold, a spokesman for the Virginia Democratic Party's coordinated campaign. "We have real questions about his motivation in doing so. It seems he is trying to scare away people from legally registering to vote. . . . What is Jeff Frederick so afraid of with legally registering new voters?"

From Jan. 1 to June 31, 147,000 people registered to vote for the first time in Virginia, according to the State Board of Elections. The pace is expected to pick up in the early fall. In Fairfax County, for example, the general registrar is processing an average of 1,800 voter registration applications a week.

Volunteers, including members of the Obama campaign, do much of the work. But a group called the Community Voters Project has been paying some of its canvassers based on how many registration forms they turn in.

Last week, Hampton police arrested three of those canvassers and charged them with voter fraud.

"These people involved were not meeting their quotas, so they started making up false information," said Cpl. Allison Good, a police spokeswoman. The city registrar's office and officials at the Community Voters Project noticed the discrepancies and contacted police, she said.

Linda D. Curtis, the Hampton commonwealth's attorney, said such arrests are "not unusual" in the weeks leading up to an election.

"From time to time, we sometimes get this," Curtis said.

Frederick said Republicans fear that the charges are part of a larger problem that could undermine the Nov. 4 election.

"We are not looking for trouble," Frederick said. "Every day we hear all these people are getting registered to vote, but we are trying to look out for the voters of Virginia and trying to look at the integrity of the process here in Virginia."

Frederick called on Gov. Timothy M. Kaine (D) and Attorney General Robert F. McDonnell (R) to launch an investigation. On Monday, both declined to begin an investigation, calling it a local matter.

Ayodele Carroo, director of the Community Voters Project, said Frederick's accusations are unfounded. "Our mission is to register minority voters to increase their participation in the political process," she said in a statement. "We have a zero tolerance policy for fraud. We take fraud very seriously and have implemented extensive checks for identifying falsified forms. We were the ones who identified the fraud and reported it to the board of elections. To twist this around as being a fraudulent campaign is outrageous."